Liquid crystal display device has been disseminated as a space-saving image display device with low power consumption, and has been expanding its applications year by year.
The liquid crystal display device is generally configured by providing polarizing plates on both sides of a liquid crystal cell. The polarizing plate functionally allows only light having a certain directionality of plane of polarization to pass therethrough, and performance of the polarizing plate largely affects performance of the liquid crystal display device. The polarizing plate is generally configured by a polarizer which is typically composed of an oriented polyvinyl alcohol film having iodine or dye adhered thereto, and translucent protective films bonded to the front and back surfaces of the polarizer.
With recent expanding applications of the liquid crystal display device, there has been an increasing trend of large-sized, high-definition applications such as television set, and this has further pushed up a level of required quality of the polarizing plate. In particular, large-sized, high-definition liquid crystal display devices have increasingly been used outdoors and under various severe environments than before. From this point of view, in recent years, the polarizing plate used for the liquid crystal display device has been strongly demanded to improve the durability of the polarizer under high-temperature and high-humidity conditions.
JP-A-2011-237580 describes that the durability of the polarizer, under high-temperature and high-humidity conditions, was improved by mixing a specific organic acid into the polarizer.
JP-A-2011-118135 describes addition of barbituric acid to the protective film.